/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: NodeSetType.java,v 1.2.4.1 2005/09/05 11:21:45 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.compiler.util;

import com.sun.org.apache.bcel.internal.generic.ALOAD;
import com.sun.org.apache.bcel.internal.generic.ASTORE;
import com.sun.org.apache.bcel.internal.generic.BranchHandle;
import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.GOTO;
import com.sun.org.apache.bcel.internal.generic.IFLT;
import com.sun.org.apache.bcel.internal.generic.INVOKEINTERFACE;
import com.sun.org.apache.bcel.internal.generic.INVOKESTATIC;
import com.sun.org.apache.bcel.internal.generic.Instruction;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.bcel.internal.generic.PUSH;
import com.sun.org.apache.xalan.internal.xsltc.compiler.Constants;
import com.sun.org.apache.xalan.internal.xsltc.compiler.FlowList;

/**
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 */
public final class NodeSetType extends Type {

  protected NodeSetType() {
  }

  public String toString() {
    return "node-set";
  }

  public boolean identicalTo(Type other) {
    return this == other;
  }

  public String toSignature() {
    return NODE_ITERATOR_SIG;
  }

  public com.sun.org.apache.bcel.internal.generic.Type toJCType() {
    return new com.sun.org.apache.bcel.internal.generic.ObjectType(NODE_ITERATOR);
  }

  /**
   * Translates a node-set into an object of internal type
   * <code>type</code>. The translation to int is undefined
   * since node-sets are always converted to
   * reals in arithmetic expressions.
   *
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      Type type) {
    if (type == Type.String) {
      translateTo(classGen, methodGen, (StringType) type);
    } else if (type == Type.Boolean) {
      translateTo(classGen, methodGen, (BooleanType) type);
    } else if (type == Type.Real) {
      translateTo(classGen, methodGen, (RealType) type);
    } else if (type == Type.Node) {
      translateTo(classGen, methodGen, (NodeType) type);
    } else if (type == Type.Reference) {
      translateTo(classGen, methodGen, (ReferenceType) type);
    } else if (type == Type.Object) {
      translateTo(classGen, methodGen, (ObjectType) type);
    } else {
      ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
          toString(), type.toString());
      classGen.getParser().reportError(Constants.FATAL, err);
    }
  }

  /**
   * Translates an external Java Class into an internal type.
   * Expects the Java object on the stack, pushes the internal type
   */
  public void translateFrom(ClassGenerator classGen,
      MethodGenerator methodGen, Class clazz) {

    InstructionList il = methodGen.getInstructionList();
    ConstantPoolGen cpg = classGen.getConstantPool();
    if (clazz.getName().equals("org.w3c.dom.NodeList")) {
      // w3c NodeList is on the stack from the external Java function call.
      // call BasisFunction to consume NodeList and leave Iterator on
      //    the stack.
      il.append(classGen.loadTranslet());   // push translet onto stack
      il.append(methodGen.loadDOM());       // push DOM onto stack
      final int convert = cpg.addMethodref(BASIS_LIBRARY_CLASS,
          "nodeList2Iterator",
          "("
              + "Lorg/w3c/dom/NodeList;"
              + TRANSLET_INTF_SIG
              + DOM_INTF_SIG
              + ")" + NODE_ITERATOR_SIG);
      il.append(new INVOKESTATIC(convert));
    } else if (clazz.getName().equals("org.w3c.dom.Node")) {
      // w3c Node is on the stack from the external Java function call.
      // call BasisLibrary.node2Iterator() to consume Node and leave
      // Iterator on the stack.
      il.append(classGen.loadTranslet());   // push translet onto stack
      il.append(methodGen.loadDOM());       // push DOM onto stack
      final int convert = cpg.addMethodref(BASIS_LIBRARY_CLASS,
          "node2Iterator",
          "("
              + "Lorg/w3c/dom/Node;"
              + TRANSLET_INTF_SIG
              + DOM_INTF_SIG
              + ")" + NODE_ITERATOR_SIG);
      il.append(new INVOKESTATIC(convert));
    } else {
      ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
          toString(), clazz.getName());
      classGen.getParser().reportError(Constants.FATAL, err);
    }
  }


  /**
   * Translates a node-set into a synthesized boolean.
   * The boolean value of a node-set is "true" if non-empty
   * and "false" otherwise. Notice that the
   * function getFirstNode() is called in translateToDesynthesized().
   *
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      BooleanType type) {
    final InstructionList il = methodGen.getInstructionList();
    FlowList falsel = translateToDesynthesized(classGen, methodGen, type);
    il.append(ICONST_1);
    final BranchHandle truec = il.append(new GOTO(null));
    falsel.backPatch(il.append(ICONST_0));
    truec.setTarget(il.append(NOP));
  }

  /**
   * Translates a node-set into a string. The string value of a node-set is
   * value of its first element.
   *
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      StringType type) {
    final InstructionList il = methodGen.getInstructionList();
    getFirstNode(classGen, methodGen);
    il.append(DUP);
    final BranchHandle falsec = il.append(new IFLT(null));
    Type.Node.translateTo(classGen, methodGen, type);
    final BranchHandle truec = il.append(new GOTO(null));
    falsec.setTarget(il.append(POP));
    il.append(new PUSH(classGen.getConstantPool(), ""));
    truec.setTarget(il.append(NOP));
  }

  /**
   * Expects a node-set on the stack and pushes a real.
   * First the node-set is converted to string, and from string to real.
   *
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      RealType type) {
    translateTo(classGen, methodGen, Type.String);
    Type.String.translateTo(classGen, methodGen, Type.Real);
  }

  /**
   * Expects a node-set on the stack and pushes a node.
   *
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      NodeType type) {
    getFirstNode(classGen, methodGen);
  }

  /**
   * Subsume node-set into ObjectType.
   *
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      ObjectType type) {
    methodGen.getInstructionList().append(NOP);
  }

  /**
   * Translates a node-set into a non-synthesized boolean. It does not
   * push a 0 or a 1 but instead returns branchhandle list to be appended
   * to the false list.
   *
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateToDesynthesized
   */
  public FlowList translateToDesynthesized(ClassGenerator classGen,
      MethodGenerator methodGen,
      BooleanType type) {
    final InstructionList il = methodGen.getInstructionList();
    getFirstNode(classGen, methodGen);
    return new FlowList(il.append(new IFLT(null)));
  }

  /**
   * Expects a node-set on the stack and pushes a boxed node-set.
   * Node sets are already boxed so the translation is just a NOP.
   *
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      ReferenceType type) {
    methodGen.getInstructionList().append(NOP);
  }

  /**
   * Translates a node-set into the Java type denoted by <code>clazz</code>.
   * Expects a node-set on the stack and pushes an object of the appropriate
   * type after coercion.
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      Class clazz) {
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();
    final String className = clazz.getName();

    il.append(methodGen.loadDOM());
    il.append(SWAP);

    if (className.equals("org.w3c.dom.Node")) {
      int index = cpg.addInterfaceMethodref(DOM_INTF,
          MAKE_NODE,
          MAKE_NODE_SIG2);
      il.append(new INVOKEINTERFACE(index, 2));
    } else if (className.equals("org.w3c.dom.NodeList") ||
        className.equals("java.lang.Object")) {
      int index = cpg.addInterfaceMethodref(DOM_INTF,
          MAKE_NODE_LIST,
          MAKE_NODE_LIST_SIG2);
      il.append(new INVOKEINTERFACE(index, 2));
    } else if (className.equals("java.lang.String")) {
      int next = cpg.addInterfaceMethodref(NODE_ITERATOR,
          "next", "()I");
      int index = cpg.addInterfaceMethodref(DOM_INTF,
          GET_NODE_VALUE,
          "(I)" + STRING_SIG);

      // Get next node from the iterator
      il.append(new INVOKEINTERFACE(next, 1));
      // Get the node's string value (from the DOM)
      il.append(new INVOKEINTERFACE(index, 2));

    } else {
      ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
          toString(), className);
      classGen.getParser().reportError(Constants.FATAL, err);
    }
  }

  /**
   * Some type conversions require gettting the first node from the node-set.
   * This function is defined to avoid code repetition.
   */
  private void getFirstNode(ClassGenerator classGen, MethodGenerator methodGen) {
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();
    il.append(new INVOKEINTERFACE(cpg.addInterfaceMethodref(NODE_ITERATOR,
        NEXT,
        NEXT_SIG), 1));
  }

  /**
   * Translates an object of this type to its boxed representation.
   */
  public void translateBox(ClassGenerator classGen,
      MethodGenerator methodGen) {
    translateTo(classGen, methodGen, Type.Reference);
  }

  /**
   * Translates an object of this type to its unboxed representation.
   */
  public void translateUnBox(ClassGenerator classGen,
      MethodGenerator methodGen) {
    methodGen.getInstructionList().append(NOP);
  }

  /**
   * Returns the class name of an internal type's external representation.
   */
  public String getClassName() {
    return (NODE_ITERATOR);
  }


  public Instruction LOAD(int slot) {
    return new ALOAD(slot);
  }

  public Instruction STORE(int slot) {
    return new ASTORE(slot);
  }
}
